Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

6 hosts · 271 ms

HostCertsFirst seenLast seenDNS
stichtingdefriesland.nl 1 2026-01-05 2026-01-05 ok
www.stichtingdefriesland.nl 1 2026-01-05 2026-01-05 ok
acc.www.stichtingdefriesland.nl 1 2026-01-05 2026-01-05 ok
stg.www.stichtingdefriesland.nl 1 2026-01-15 2026-01-15 ok
acc.stg.www.stichtingdefriesland.nl 1 2026-01-15 2026-01-15 ok
1.tst.www.stichtingdefriesland.nl 1 2026-01-05 2026-01-05 ok

Programmatic access, with DNS A records: API GET /v1/hosts/stichtingdefriesland.nl (API key for paging).

Shown here: hostnames with a certificate that is valid now or expired within the last 90 days. The full history since 2013 — hostnames whose last certificate expired earlier — is a Pro plan method: GET /v1/hosts-history/stichtingdefriesland.nl.